A Swarm Greater Than Its Parts
Many years ago, while living in San Francisco, I came home on a Sunday evening to my apartment after a most enjoyable motorcycle ride through vineyards of Sonoma Valley that included a few stops along the way. To my great surprise, upon turning the light on in my kitchen, I saw a thick, black superhighway of tiny ants starting under my kitchen door, going all across my floor, up six feet of shelving, covering a bottle of maple syrup and then back down and out the door. My friend who was with me and happened to be a zoologist, coolly commented that these were Argentine ants and that they were not like typical ants with one queen in an ant colony. Rather, the Argentine ant, officially known as Linepithema Humile, moves constantly and has many queens. In fact, the Argentine ant holds the crown as the most invasive ant species in the world, inhabiting almost every continent on earth. Apart from being disgusted by the silent ribbon of ants in my place, I truly found this swarm of purposeful creatures fascinating.
Entomologists continue to study and seek to understand how ants function as a collective group that has no central organizing leader. In most cases, the colony serves the queen, but the queen does not have a group of dedicated administrators that tell each ant what to do. Individual ants will respond to their environment and to chemical signals called pheromones emitted by other ants they run into. For example, an ant that has returned from a food source will emit a pheromone combination that tells another ant to start gathering food. The second ant without food will follow a trail of scent laid down by the first ant. Ants are versatile, and each ant can perform tasks like foraging, shuttling baby ants around, nest building and more. Following simple signs from one individual to another gives the colony a unique ability to thrive without instructions or commands coming from some command center. The ability of ants to build massive colonies, avoid danger and invade continents without a central leader has been termed “swarm intelligence”.
Swarm intelligence is often described as the amplified intelligence of groups of animals such as birds form flocks, fish form shoals and ants form colonies. A fish or an ant may not be very intelligent individually, but their swarm avoids predators or builds magnificent homes like a termite colony or honeybee hive. The nature of swarm intelligence not only intrigues biologists but has captured the imagination of computer scientists and robotics engineers as well. The idea that simple robots that react to their environment and to each other as a collective or swarm to amplify their intelligence drives research today and forms a new branch of artificial intelligence. There are a number of different ways scientists are already using swarm intelligence in robotics. In the agriculture industry, David Dorhout believes that the future of agriculture may depend on armies of cheap little robots equipped with sensors and some basic rules to replace massive farm machinery and human workers. He envisions little bots using swarm intelligence to plant, tend and harvest various crops. There will not be some complicated central planning programs that tell the bots were to go and plant. Rather, the bots will sense where other bots are and move to open spaces to plant seeds and detect when moisture is low and water individual plants. Mr.Dorhout calls his company Dorhout R&D and his farm bot Prospero. According to an article in New Scientist, the US military envisions using robot swarms in removing mines and for search and rescue without human intervention. The medical community also envisions employing swarm intelligence at the level of tiny nanoparticles for treating cancer. The nanoparticles would be small enough to pass through a blood vessel into cancerous tissue and smart enough to recognize it.
Swarm intelligence observed in nature in the form of ant colonies, bird flocks, and fish shoals demonstrates how the actions of individuals together without a central organizer amplify their collective intelligence that becomes smarter than the individual’s. The collective intelligence observed in the natural world inspired a new discipline in artificial intelligence that seeks to use collective behavior to empower simpler robots to work together for a common goal. Swarm intelligence may also contribute to saving lives in the medical field and making agriculture more efficient. Perhaps we may eventually see a certain beauty in many robots cooperating in a swarm.